Percussive drill.



o. c. HANSEN. PBRGUSSIVE DRILL.

APPLIGATION FILED MAY 3l, 1912.

Patented Apr. 14, 1914 NVEIVTOI? W/TNESSES: am u? Zaai @U1 www.

l TTOH/VEY Assiefnon. rro induisent-nani) GRADI-ES C. HANSEN, 0F

COMPANY, OF NEW YORK, N. Y., JERSEY.

EEBGUSSIVE DRLL.

Speciiieation of Letters Patent. Patented Api'. Mt, 1914i Appiication mea nay si, i912. sensi no. 700,635. /d

1 in which reciprocates a piston 2, the movement of which is controlled by a valve 3 of any desired construction. he forward end ef the piston consists of a luted bar which is of smaller 1 than the main portion of the piston 'leaving a shoulder against which the operating il ward of the cylinder proper the interiory of the cylinder casing To all whom it may concern:

Be it known that I, CHARLES C. HANSEN,

a ycitizen of the United States, residing in Easton, in the county of Northampton an State of Pennsylvania, have invente certain new and useful improvements in Perof which the following is a cussive Drills, specification.

This invention relates to percussive drills and more particularly to a front head an leaving a shoulder against Win@ abuts a buffer construction for drills of the type metelbller 01 pa0kmg ring 5. In the front shown as for instance in par@ ts t0 Leyner, of this and slightly separated from it eX- 65 Nos. 651,487', 709,022 and 739,55 In drills cept atthe end of the forward stroke 0f the of this type the forward stroke of the p'islSten 1 5 a sleeve 6 provided with a flange 7 ton is not Cushioned by the operating' Hui which is in sliding contact with the inner and under normal drilling conditions the Surface of the cylinder casing 1 Between piston is kept from hitting the from, 0f the, the ring 5 and the flange 7 is a helical spring. 70 cylinderlbecause it rst strikes the drill 8 Winch teDdS t0 keep these parts Separate steel which is in Contact with the work. as Shown in Fig. 1n front of the flange 7 Under some conditions however the piston and Contacting with it is a sleeve 9 whic is reciprocated when the steel is not in con- S3311 mOVe 10ng1t11dinelly in the cylinder cas-l taet with the work, as when the drill is being 1 but is prevented from rotary move- 75 in cranked back out of a hole. [n such a ment by the pin 10 engaging the flange 11 Case the piston hits the front end 0f the, vCyl- Wli'iCh abuis the forward end O the Cylinder inder with considerable force. In drills Casing l. p heretofore used this impact of the piston on Rotata ly mounted'in the sleeve 9 is a tool the front of the cylinder has been cushione` sleeve 12 whichis provided with a chuck 13 80 by a stationary heavy ring of rubber, which into which tits the back' end of the drill has proved unsatisfactory for several reasteel 14:. Abutting against the forward end sons, and also by s idably mounting the of tool sleeve 12 is a drill steel retaining ring 15 over w ic fits the front hea through which pass bolts 17.- heads 18 of bolts 17 and the front head cap 16 are springs 19 which serve to ieee 16 and the flange 11 of sleeve 9 resiliently against the front end of the cylinder whole front part and securing it resiliently by outside o the cylind is has proved unsatisfactory also as the inertia of the front consider,-

ctive not only to the front end of the iston but to the part casing l. U directly receiving the low. In the operation of the drill of the shoul- The object of the present invention is to der L1 of the piston strikes the ring 5 it will rovide a means whereby the rubber ring move it forward slightly against the cushcan be eliminated and the disadvantages o ioning pressure of the spring 8 which is the spring construction largel obviate sufficiently strong tto give the sleeve and have part of the drill a With this object 'in view I devised a construction a practi al embodiment of which slight start forward before the ring 5 conis shown in the accompanying drawings in tacts wi h the rear end of sleeve After which: this contact is made the further movement Figure in section snowing the piston at forward vertical i longitudinal H-H of Fig.

on its back stroke.

The drill as shown comprises ment of the entire forward except cylinder casing 1 against the cushioning pressure of the springs 19 until the the cylinder pressed in the this way the impact of the piston on the forward part of the drill is taken up gradually and without excessive shock.

t is to be understood shown and described discloses only one modification of my drill and What I claim is:

' n a percussive drill, a cylinder, its piston, a buffer for said piston, drill steel olding means, said buffer and drill steel holding means being longitudinall ment o said so positioned as to contact steel holding means after movement, resilient means for said a sleeve g means, and s eeve being movable longitudinally of said yieldably holding said buffer,

means forward -sa1d plston contacts near and resilient means yieldably holding said steel holding means against forward movement. r

3. In a percussive drill, a cylinder, its piston a resiliently held buffer against which said piston contacts near the forward end of its stroke, movable drill steel holdin of said bu er, positioned to be engaged by said buffer after slight move- ,ment of said buffer, and resilient means opposing forward movement of said drill steel o ding means.

n a percussive drill, a cylinder, its piston, a resiliently held buffer against which the forward end of its stroke, movable drill steel holdin means forward of said buffer, positioned to slight movement of said buffer, a front head ca Witnesses:

HARRY D. POWELL, WM. C. MORRIS.

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